Cataract progression seen after prophylactic peripheral iridotomy

Prophylactic laser peripheral iridotomy in the fellow eyes of patients with acute primary angle closure is associated with significant cataract progression, according to a study in Asian eyes.

Lawrence S. Lim, MBBS, and colleagues at the Singapore National Eye Center reported on their observations in 60 Asian patients with unilateral acute primary angle closure. Most patients were Chinese (85%), and almost two-thirds were women. The average age was 61 years.

All fellow eyes underwent prophylactic laser peripheral iridotomy within the first week of presentation, after which the patient was prescribed 1 week of topical steroids. Opacity classification and standard color photography was used as the reference for grading lens opacity, performed at 2 weeks, 4 months and 12 months after laser peripheral iridotomy. Cataract progression was defined as an increase by 2 or more units on the Lens Opacity Classification System scale in any lens region.

With 12 months of follow-up, 14 eyes (23.3%) showed significant progression in any lens region. Progression in the nuclear region was 5%, in the cortical region 6.7%, and in the posterior subcapsular region 16.7%.

“Eyes in which significant cataract progression occurred were associated with a decrease in visual acuity of about 0.1 logMAR. … In contrast, eyes without significant cataract progression maintained essentially unchanged visual acuities,” the researchers said in the study, published in the August issue of Ophthalmology.

“Although we do not dispute the importance of performing laser peripheral iridotomy in fellow eyes of patients with acute primary angle closure to prevent an acute attack, we believe our findings may have potential implications for the role of prophylactic laser peripheral iridotomy in the prevention of angle-closure blindness,” the authors said.